Effects of IgE and complement on the protective immunity against helimth infections.

为了分析针对蠕虫感染的保护性免疫，我们研究了IgE和补体的作用。免疫球蛋白E基因缺陷小鼠的寄生虫感染：日本海膜吸虫和日本血吸虫被选为诱导产生抗寄生虫抗体的寄生虫。用免疫球蛋白E缺陷的SJA/9小鼠和产生免疫球蛋白E的对照SJL/J小鼠比较免疫球蛋白E的作用。在H.nana感染中，IgE抗体对血嗜酸粒细胞数无影响，但对成虫的排泄有部分作用。在日本血吸虫感染中，IgE抗体似乎与肝脏虫卵肉芽肿的形成部分相关。选择巴西拟圆线虫和马来丝虫作为诱导增强免疫球蛋白产生的蠕虫。SJL/J感染组小鼠血清总IgE水平高于未感染组的10倍以上，而SJA/9组未检测到。感染后两只小鼠均未检测到抗人IgE抗体。血嗜酸性粒细胞增多症和保护性免疫不被S…SJA/9和SJL/J之间的差异更显著，提示增强型IgE对嗜酸性粒细胞增多性和保护性免疫无影响。这些事实表明，除IgE外，其他因素对蠕虫感染宿主的嗜酸性粒细胞增多症和保护性免疫起主要作用。Clq对抗体依赖性细胞毒作用(ADCC)的影响：Clq促进以纤毛虫微丝虫为靶细胞、IgE抗体和多形核白细胞为效应细胞的ADCC反应。这种增强的机制被认为是通过Clq分子的尾部区域激活效应细胞和增加Clq分子头部区域与IgE抗体的结合。在后一种情况下，Clq明显增强了低亲和力抗体与抗原的结合。这一发现在低亲和力抗半抗原IgE单抗与半抗原结合的系统中得到了证实，在高亲和力单抗存在的情况下，Clq可增强半抗原与该半抗原的结合。这些结果表明，在相对大量的低亲和力抗体存在的情况下，ClQ可能在感染后的早期阶段增强了保护性免疫。较少

In order to analyse the protective immunity agagainst helminth infections, effects of IgE and complement were investigated.1. Heleminth infections in IgE deficient mice: Heymenolepis nana and Schistosoma japonicum were selected as the parasites inducing anti-parasite IgE antibody production. IgE deficient SJA/9 mice and IgE producing control SJL/J mice were used to compare the effects of IgE. In H.nana infection, IgE antibody had no effect on blood eosinophilia, but had partial effect on expulsion of adult worms. In S. japonicum infection, IgE antibody seems to relate partially to the egg granuloma formation in the liver. Nippostrongylus brasiliensis and Brugia malayi were selected as the helminths inducing potentiated ige production. total IgE level in infected mice increased 10 times higher than uninfected level in SJL/J, but did not detected in SJA/9 mice. Anti-hel-minth IgE antibody was not detected in both mice after infection. Blood eosinophilia and protective immunity were not s … More ignificantly different between SJA/9 and SJL/J, suggesting that potentiated IgE had no effect on eosinophilia and protective immunity. These facts indicate that factors other than IgE are mainly operative on eosinophilia and protective immunity in the hosts with helminth infection.2. Effects of Clq on antibody dependent cellular cytotoxicity(ADCC): Clq enhanced ADCC reaction with microfilaria of dilofilaria immitis as a target, IgE antibody, and polymorph nuclear leukocytes as effector cells. Mechanisms of this enhancement were considered to be activation of effector cells by tail region of Clq molecules and increase of IgE antibody binding by head region of Clq. In latter case, it was evident that binding of low avidity antibodies to antigen was enhanced by Clq. This finding was confirmed by the system where binding of low affinity anti-hapten IgE monoclonal antibody to the hapten was enhanced by Clq in the presence of high affinity monoclonal antibody. These results suggest the possibility that Clq enhances protective immunity in the early phase after infection at the presence of relatively large amount of low avidity antibodies. Less